A magnetoresistive angle sensor consisting of a magnetoresistive sensor and a permanent magnet encoding disc may be applied to fields such as magnetic encoders and rotational position sensors, and in general cases, planar X-Y type magnetoresistive angle sensor chips are used for magnetoresistive sensors such as TMR and GMR. Measurement of a rotation angle of the permanent magnet encoding disc is implemented by measuring X-direction and Y-direction magnetic-field components on a same chip and calculating an angle between the X-direction magnetic-field component and the Y-direction magnetic-field component. However, it mainly has the following problems:
1) When the X-Y type magnetoresistive angle sensor chip measures an angular position together with a circular permanent magnet encoding disc, a measurement plane of the chip is located above a position parallel to a rotation plane region of the circular permanent magnet encoding disc, and a sensitive magnetic field measured by the chip comes from a magnetic field of the circular permanent magnet encoding disc distributed above the rotation plane region of the circular permanent magnet encoding disc; therefore, a mounting space and a magnetic field homogeneous region of the X-Y magnetoresistive angle sensor chip are limited, and spatial flexibility is poor.
2) The distribution of a rotating magnetic field, above the rotation plane, of the circular permanent magnet encoding disc of the X-Y type magnetoresistive angle sensor chip is easily interfered by a nearby magnet such as a soft magnetic material or a permanent magnet; as a result, an angle measurement region is changed, a correct measurement angle cannot be obtained, and the stability is poor.